COMBINATION HADAMARD TRANSFORM AND RAMAN SPECTROSCOPY WITH SPECTROSCOPIC ELLIPSOMETERY FOR IN SITU ...

TTL TECHNIQUES HAS INTRODUCED HADAMARD/RAMAN SPECTROSCOPY (HRS) AS A DIAGNOSTIC TOOL TO MONITOR THE DEPOSITION ENVIRONMENT IN LOW TEMPERATURE PLASMA ASSISTED METAL ORGANIC CHEMICAL VAPOR DEPOSITION (PAMOCVD) OF MERCURY CADMIUM TELLURIDE (HGCDTE). HRS CONFIGURED TOGETHER WITH OPTICAL EMISSION SPECTROSCOPY (OES), ATOMIC ABSORPTION SPECTROSCOPY (AAS), GLOW DISCHARGE MASS SPECTROSCOPY (GDMS), AND SPECTROSCOPIC ELLIPSOMETRY (SE). THE ELECTRIC FIELDS, GAS SPECIES TEMPERATURES AND VELOCITIES AND CONCENTRATIONS WILL BE STUDIED AND THEIR RELATION WITH GAS PHASE CHEMISTRY, SURFACE CHEMISTRY AS MODIFIED BY ENERGETIC PARTICLE OR PHOTON BOMBARDMENT, FILM STOICHIOMETRY, AND BONDING STRUCTURE, PROPERTIES, AND THE PLASMA/MATERIAL SURFACE PROPERTIES AND DEPOSITION CHARACTERISTICS OF HGCDTE PAMOCVD WILL BE STUDIED. THE OBSERVATIONS MADE BY THE HADAMARD/RAMAN SPECTROMETER MONITORING TECHIQUE ARE OBTAINED BY MEASURING THE INTENSITY OF LIGHT TRANSMITTED THROUGH THE REACTOR AS WELL AS THE LIGHT SCATTERING EFFECTS OF VARIOUS GASES. IF THE ABSORPTION, EMISSION, AND SCATTERING SPECTRUM OF THE OUTPUT CORRELATES WITH KNOWN GASES, THE CONCENTRATION OF EACH INDIVIDUAL REACTANT GAS CAN BE DETERMINED. THE DEVICE CAN BE BUILT INEXPENSIVELY, IS HIGHLY ACCURATE, AND CAN MEASURE VERY LOW GAS CONCENTRATIONS AT MULTIPLE CHAMBER LOCATIONS SIMULTANEOUSLY WITH A SINGLE INSTRUMENT. THE RELATIONSHIP BETWEEN THE RESULTS OF RHS AND TEMPERATURE, GAS FLOW RATES, CONCENTRATION OF INLET GASES WILL BE ESTABLISHED AND USED TO DEVELOP FEEDBACK CONTROL PARAMETERS BY A COMPUTER. THE OPTICAL PROPERTIES AND DIELECTRIC FUNCTION OF THE HGCDTE THIN FILM WILL BE MEASURED IN REAL TIME BY SE AND WILL BE RELATED WITH OPERATIONAL CONDITIONS OF THE MOCVD. LOW TEMPERATURE PLASMA ENHANCED MOCVD (PEMOCVD) WILL BE STUDIED IMPLEMENTING A UNIQUE CONFIGURATION OF IN-SITU OPTICAL EMISSION (OE) ATOMIC ABSORPTION (AA) SPECTROSCOPY AND GLOW DISCHARGE MASS SPECTROSCOPY (GDMS). ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - DEVELOPMENT